Thermostat



l1g- 8, 1939. G. w. WHITEHURsT 2,168,836

THERMOS TAT 2 Sheets-Sheet l Filed Nov. 5, 1937 Aug. 8, 1939. G. w.wHlTEHuRsT THERIOS TAT Filed Nov. 5, 1937 2 Sheets-Sheet 2 Patented Aug.8, 1939 UNITED STATES PATENT OFFICE 13 Claims.

This invention relates to a thermostat, and aims to provide, in a manneras'hereinafter set forth,

a device of the class referred to which is quickly responsive to suddenchanges in temperature; easily and cheaply made; capable of operating ina satisfactory manner in any position which it may be set; of a size tooccupy a small space; of sturdy construction; and adaptable for lightand heavy work.

'I'he invention further aims to provide, in a manner as hereinafter setforth, a thermostat capable of being used for and in connection withthat type of oil burner which does not require electrical operations forcontrol.

The inventionfurther aims to provide, in a` manner as hereinafter setforth, a thermostat which is for use on light and heavy duty circuits;capable of being adjusted to close tolerance in temperature control; andso formed to make positive quick contact, as well as opening and closingwith the same degree of snap.

To the above ends essentially and to others which may hereinafterappear, the invention conssts of the novel construction, combination andarrangement of parts as will be more specifically referred to andillustrated in the accompanying drawings wherein are shown embodimentsof the invention, but it is to be understood that changes, variationsand modifications may be resorted to 30 which fall within the scope ofthe invention as claimed. In the drawings Figure 1 is a side elevationof a thermostat in accordance with this invention,

Figure 2 is a top plan view thereof,

Figure 3 is a section on line 3 3, Figure 1,

Figure 4 is a section on line 4 4, Figure 1,

Figure 5 is a section on line 5 5, Figure 1 when the device is adjustedfor quick snap action,

Figure 6 is a section on line 5 5, Figure 1 when the device is arrangedfor slow action,

Figure 7 is a section on line 1 1, Figure 1,

Figure 8 is a section on line 8 8, Figure 1,

Figure 9 is a fragmentary view in side elevation of a modified form,

Figure 10 is a side elevation of a modified form of thermostat, inaccordance with this invention, disposed horizontally and with thehousing for the elements of such thermostat illustrated in longitudinalsection,

Figure 1l is a section on line II I I, Figure 10,

Figure l2 is a section on line I2 I2, Figure 10,

Figure 13 is a section on line I3 I3, Figure 10,

Figure 14 is a `section on line I4 I4, Figure 10,

(Cl. 20G-138) Figure 15 is a vertical sectional view of another modifiedform, and

Figure 16 is a top plan view of the structure shown in Figure 15.

Referring to Figures 1 to 8 of the drawings, the thermostat Iillustrated thereby is adapted to be connected to a base 2 which may beof any suitable form, shown by way of example as consisting of astraplike member of angle form of the desired length and Width and ofrectangular contour in transverse cross section. The said memberincludes a pair of end parts 3, 4 disposed in parallel planes andconnected together by an inclined intermediate part 5. The part 3 is ofless length than part 4 and is formed with a 1 screw-threaded opening 6centrally thereof. Thel part 4 is provided with spaced aligned openingsI for the passage of holdfast means, not shown for anchoring the base toa support.

The thermostat I includes a pair of thermostatic bars 8, 9 disposed inparallel spaced relation. The bar 9 is of greater length than the bar8.y The bars have their elements I0 of greatest expansion arranged onand throughout their inner sides. The bars at the end portions IIthereof have aligned openings I2, which also align with the opening 6 inthe base 2. Arranged between the end portions II of the bars is a spacerblock I3 formed with a. passage I4 having its ends aligning with theopenings I2. The bars 8, 9, spacer I3 and base 2 are connected togetherby a holdfast means I5 extending through openings I2, passage I4 andhaving threaded engagement with the wall of opening I5` The bars 8, 9are formed with aligned openings I6, I1 respectively. The opening I6 isof greater diameter than the opening II. Extending through the latterand anchored to bar 9, as at I8 is an adjusting screw I9, which alsoextends through, projects above and is of less diameter than the openingI6. Threadedly engaging with that portion of the screw I9 which projectsabove opening I6 is an adjusting nut 20. Surrounding the screw I9 andinterposed between bar 8 and nut 20 is a coiled tensioning spring 2|.The bar 8 in close proximity to its ,end 22 is provided with a pair ofspaced parallel positioning pins 23 of a length to extend above and todepend below bar 8. The latter is formed with an opening 24 interposedbetween the opening I 6 and the end 22 thereof. The purpose of theopening 24 will be referred to.

The bar 9 in proximity to its end 25 is formed with a screw-threadedopening 26 and inwardly adjacent the latterwith an opening 21 of greaterferred to.

diameter than the opening 26. Positioned on the inner side of bar 9 andprojecting beyond the end 25 of the latter is a rectangular block 28 ofinsulation provided with openings 29, 30 and 3|. The openings 30, 3|align with the openings 26, 21 respectively of the bar 9. The block 28is anchored to the bar 9 by a tie bolt 32 threadedly engaging with thewalls of the openings 26 and 30. Extendin g through the opening 29, aswell as threadably engaging with they block 28 is a binding post 33provided at its upper end with a contact 34. Threadably engaging withthe wall of the opening 3|, extending in the opening 21 and projectingabove the block 28 is a travel controlling screw 35 for a circuitopening and closing member to be referred to. The lower end of the screw35 is spaced from the wall of opening 21. The screw 35 is of greaterlength than the bolt 32 and has its head 36 spaced above the block 28.

The thermostat l includes a combined snapping, snap regulating andcircuit opening and closing mechanism generally indicated at 31 andwhich is arranged above and below the bar 8, as well as projecting fromthe latter to over the contact 34. The mechanism 31 is to normallyengage the contact 34. The mechanism 31 includes a pair of superposedcompression levers 38, 39, the former being arranged above and thelatter below the bar' 8 and positioned at one end between the pins 23 isa pair of oppositely disposed shifters 40, 4| of like form and eachconsisting of a horizontally disposed part 42 and an outwardly inclin'edpart 43. The shifters are constructed of light spring metal and are ofconcavoconvex contour in transverse cross section. The parts 42 oftheshifters are arranged between the pins 23. The part 42 of shifter 40 ispositioned on the outer side of bar 8 below the lever 38. The part 42 ofthe shifter 4| is positioned against the inner side of the bar 8 andabove the lever 39. The parts 42 of the shifters are anchored -to thebar 8 by a securing pin 44 which extendsv 'above part 42 of shifter 49and depends below part 42 of shifter 4|. The pin 44 is upset at each endto provide the heads 45, 46 for a purpose to be re- The pin 44 extendsthrough the levers 38, 39, which are provided intermediate their endswith openings 41, 48 for the passage of the pin 44. The heads 45, 46provide Vfulcrums for the levers 38, 39 respectively. The lever 38 isformed with a screw-threaded opening 49 which aligns with the opening24. Threadably engaging with the wall of the opening 49, extendingthrough opening 24 and seated on lever 39 is an adjustable snapregulating screw 50.

The mechanism 31 includes a .coupling block 5| of insulation materialprovided with a transverse groove 52 opening at its sides and at oneend. The block 5| tapers in opposite directions to provide points53,-and extends between and has its points 53 bear against the innersides of the parts 43 of the shifters in proximity to the free ends ofsuch parts. The parts 43 of the shifters are connected to the block 5|by the securing pins 54. The block 5| is arranged above and spaced fromthe block 28. Extending into the groove 52 and anchored to the block 5|by the holdfast means 55 is a circuit opening and closing member 56 of alength to extend over contact 34. The

. member 56 is provided withan opening 51 through which extends theshank of the screw 35. The

opening 51 is of greater diameter than saidv the latter is moved fromcircuit closing position. The member 56 is provided on its inner facewith a contact 58-which coacts with the contact 34 for the purpose ofclosing the circuit when the contacts are in engagement. A binding post59 is connected to member 56 and has its inner end provided with thecontact 58.

With reference to the modied form shown in Figure 9, and indicated at60, it is of the same construction as the form shown in Figure 1 withthis exception that the thermostatic bars 6|, 62 have their elements 63of greatest expansion arranged on the outer sides of the bars. Otherwisethan that as stated, the form shown in Figure 9 will be the same as thatshown in Figure 1.

The thermostat is of a form to break the contact when a predeterminedmaximum degree of temperature acts thereon. 'Ihe thermostat 60 is of atype to break the contact when a predetermined minimum degree oftemperature acts thereon. The function referred to with respect tothermostat is due to the manner in which the elements of -the greatestexpansion of the thermostatic bars 8, 9 are arranged on said bars. Thefunction referred to in connection with thermostat 60 is due tothemanner in which the elements of least expansion of the bars 6|, 62 arearranged on said bars. With respect to the thermostat the elements I0 ofthe thermostatic bars 8, 9 when maximum temperature is reached willcause the non-anchored ends of the bars to move apart from each other.With respect to the thermostat 60 the elements 64 of least expansionwhen minimum temperature is reached will cause the non-anchored ends ofthe bars to move apa-rt from each other. When the non-anchored ends ofthe thermostatic bars move away from each other, the contacts 34, 58 aremoved out of contacting relation.

The adjusting screw I9, nut 20 and spring 2| are for the purpose ofadjusting or placing the thermostatic bars 8, 9 in their correct ordesired position to govern a desired or certain temperature setting sothat the contacts 34, 58 are opened and closed at the desiredtemperature.

The parts 42, 43 respectively of the shifters 40, 4| are termed Shanksand heads respectively. The shanks are held stationary against oppositesides of the bar 8.

shifters at the point of mergence of said Shanks with said heads. Theheads extend from bar 8 and are inclined outwardly in oppositedirections. The heads are capable of bending or snapping in unison inlike directions with respect to the shanks. The bending or snappingmovement of the heads is an oscillatory one and such movement providesfor a snap opening or closing movement relative to the contacts 34, 58.This movement in relation to the contacts is regulated in a manner to bereferred to. v

The screw 5|) of the mechanism 31 is for the purpose of applying varyingpressure on one end of the lever 39. The purpose of this pressurevariation is to provide for the ends A of the levers 38, 39 to move outrelative to the shanks of the shifters to allow the full curve of theheads of the shifters to exist, and when resistance to the compressioneffort on the part of the levers is overcome, the heads give away with aquick snap or `suddent movement. The snap of the heads is controlled bythe extent of reducing the curvature of the heads. The greatest snap ishad when the curvature of the shifters is as shown in Figure 5.

The levers 38, 39 act at one -l end thereof for compressing the body ofthe The movement of the snap gradually decreases until the shiftersassume a flatcross section as shown in Figure 6. The shifters aremounted in a manner to provide a counterbalance in their resistance toeach other and produce a very acute dead center or balance of effort andcannot be positioned on their dead centers. When this dead center pointis reached very little effort is required to alternate the movement ofthe contacts to or from each other quickly and firmly, and the degree ofquickness and firmness of the contact points movement can be varied bycompressing the shifters until they assume a fiat position such as shownin Figure 6 and then the heads possess no snapping action at all.

With reference to Figure 1, the thermostat is illustrated in a nearneutral position with contacts 34, 58 spaced from each other. 'I'he heatwill cause the bars 8, 9 to separate at their free ends whereby member56 will be shifted to bear against the head 36 of screw 35 and undersuch conditions the alternate movement of such member will be arrestedand as the flexing point of the mechanism is at A the effort of the bars8, 9 vacts to break the back of shifter 40 at B and allows shifter 4| atC to straighten up and thus provides for the shifters 40, 4| to snap thecontacts 34, 58 4into engagement. The reverse order of operation opensthe contacts.

The arrangement of the parts of the thermostat I provides for a sturdyconstruction andyet permits a very delicate and close setting oftelnperature control. The statement applies to the modified form shownin Figure 9.

With reference to the modified form of thermostat 65 shown in Figures 10to 14 both inclusive, it includes a cylinder or housing 66 open at oneend and closed at its other endf by a cap 61. Mounted on and extendedfrom the open end of the housing 66 is a peripherally threaded mountingnipple 68. The elements 66, 61 and 68 may be formed of any suitablematerial. The thermostat 65 is to be horizontally disposed and includesa depending means to be referred to for controlling a valve mechanism orother suitable device, more particularly an oil level controlling andfuel regulating mechanism for oil burners.

Arranged within the housing 66 abutting against the cap 61 and seatingon the inner face ol` the nipple 68 is a base 68 of strap-like form ofthe desired thickness and Width. The base 69 is of angle contour andincludes an upstanding leg 1|] and a horizontally disposed leg 1| havingits end terminal portion 12 offset outwardly with respect to itsremaining portion. The leg 10 snugly abuts against the inner face of thecap 61. A part of the leg 1| snugly abuts against the inner face of thebottom of the housing 66 and a part of the offset terminal portion' ofleg 1| snugly abuts against the inner face of the bottom of the nipple68. The terminal portion 12 o f the leg 1| is anchored to the nipplev|58 by the holdfast means 13.

The thermostat 65 includes a pair of thermostatic bars 14, 15 disposedat parallel spaced relation and with the bar 14 projected beyond one endof the bar 15. The element of each of the bars of greater expansion isindicated at 16 and l it is arranged on the inner side of each bar. Thebars 14, 15 abut the leg 10 of the base 69. Interposed between said barsis a spacer block 11 of any suitable material which abuts the leg 10 ofbase 69. Interposed between the bar 15 and the leg 1| of the base 69 aswell as abutting leg 10 is a spacer block 18 of any suitable material.

The bar 14, block 11, bar 15, block 18 and leg 1| have aligned openings19, 80, 8|, 82 and 83 respectively. The wall of the opening in the leg1| is screw-threaded. Extending through the aforesaid aligned openingsand threadably engaging with the wall of the opening is a headed tiebolt 84 functioning to connect the thermostatic bars, the spacer blockand the base 69 together.

Anchored to the bar 15 and extending upwardly through an opening 85 inthe bar 14 is a positioning pin 86 of a diameter less than the diameterof the opening 85. Anchored at its lower end in the bar 16 in proximityto the free end of the latter is a vertically disposed adjusting screw81 which extends upwardly through an opening 88 in the bar 14.Threadedly engaging with the upper portion of the screw 81 is anadjusting nut 89 and interposed between the latter and the bar 14, andsurrounding the screw 81 is a coil tensioning spring 9|).

The thermostat 65 includes a shifting arm 9| for the mechanism which isto be controlled by the thermostat. The arm 9| has its body formed oflike material from which the bars 14, 15 are formed. The arm 9| projectsoutwardly from the nipple 68 and is provided at its inner end with anotch 93, at its outer end with an opening 94 and intermediate its endswith an opening 95. The pin 86 extends through the notch 93 and is ofless diameter than the width of such notch. The screw 81 extends throughthe opening 95 and is of less diameter than the diameter of suchopening. The arm 9| fulcrums on the free end of the bar 15.

The element 92 is shown by way of example as a lift rod 96 having aperipherally threaded upper portion carrying an adjusting nut 91 forabutting the outer end of arm 9|. As the elements of greatest expansionof the bars 14,'15 face each other, the heat, at and above maximumtemperature causes the outer or free ends of the bars 14, 15 to separateo1' travel further apart. The screw 81, nut 89 and spring 90 areemployed for adjusting the bars 14, 15 to provide for the thermostat tooperate at any desired temperature setting. The arm 9| is also athermostatic bar, A

but has the element thereof of greatest expansion on its upper side. Thearm 9| in proportion to the length of the part inserted between the bars14, 15, from pin 86 to screw 88 and from the screw 81 to its outer endor nut 91 determines the amount of travel between the free ends of thebars 14, 15 and it also magnies the travel at the service ends of thethermostatic bars or the element 92. threaded upper terminal portion ofthe bar 96 provides for the adjusting of the element 92 relative to arm9| thereby providing an additional adjustment to the device which is tobe controlled from element 92.

With respect to the modified form of thermostat 98 shown in Figures 15and 16, it is of the same construction as the thermostat with thisexception that it is so disposed to provide for the verticalv moving ofthe actuating or multiplying movement arm 99 for the element '|00 whichit lifts and lowers. vThe arm` 99. is formed of the same material as'thearm 9|, but it is of angle form and includes an upstanding branch IUIdisposed at an inclination to the vertical'and a horizontally disposedbranch |02 extending outwardly at right angles to the upper end of thebranch IUI. The .element |00 is carried by the branch |82. The element|00 is of the same form as The nut 91 in connection with the Cil InFigures 15 and 16 the housing, which is vertically disposed is indicatedat |03, the closure cap for one end of the housing at |04, the base |05,the thermostatic bars at |06, |01, the spacer blocks |08, |09, theadjusting means for the bars |06, |01 at ||0 and the nipple at ill. Thebase |05 is disposed vertically, but it is of the same form as the base69. As aforesaid, the construction of the thermostat 98 is the same asthat of the thermostat; 65, with the exceptions that the thermostat 98is vertically disposed and the arm 99 which corresponds to the arm 9| isof angle contour.

With respect to the thermostat 65, when the bars 1d, l5 thereof moveapart at their free ends it allows for the inner end ofthe arm 9| whereit is pressed against the inner face of bar 'lll to move up and as arm9| fulcrums on bar l5, that arm 9| at such point rocks and permits amagnified downward movement to the outer end of arm 9| and as the latteris of thermostatic bar-like form, it also adds its movement to the nut97.

It is obvious that by placing the least expansive elements of thethermostatic bars 14, 'l5 face to face, and reversing the position ofthe greatest expansive element of the arm 9|, a reverse movement of thenut 91 will occur on heat and by this arrangement control may be had forlift on cold,

l or for lift on heat.

What I claim is:

1. In a thermostat, a pair of thermostatic bars, means for anchoring oneend of the bars together and for maintaining them in parallel spacedrelation, one of said bars being of greater length than and extendedbeyond the other end of the-other bar, that bar of greatest length beingprovided with a contact positioned beyond the bar of shortest length,and a combined snapping, snap regulating and circuit opening and closingmechanism carried by the bar of shortest length for coaction with saidcontact and having its operation controlled by the thermostaticmovements of said bars.

2. The invention as set forth in claim 1 having said mechanism providedwith controllable oppositely disposed bodily depressible shifters ofconcavo-convexo contour in transverse cross section.

3. The invention as set forth in claim 1 having said mechanism providedwith controllable oppositely disposed bodily depressible Shifters oflike form and of concavo-convexo contour in transverse cross section,each of said shifters including a shank and a head, said heads moving inlike direction with respect to said shanks on the operation of saidmechanism.

4. The invention as set forth in claim 1 having said mechanism providedwith fulcrumed pressure applying levers and oppositely disposed shiftersof like form and of concavo-convexo contour in transverse cross sectionhaving their movement controlled by said levers.

5. In a thermostat, a pair of thermostatic bars, means for anchoring oneend of said bars together and for maintaining the bars in parallel saidmechanism provided with controllable oppositely disposed bodilydepressible resilient shifters of concavo-convexo contour in transversecross section, said shifters being connected with said member.

'1. In a thermostat, a pair of spaced thermostatic bars, means foranchoring one end of the bars together and for maintaining. the bars inspaced relation, one'of said bars being of greater length than andextended beyond the other end of the other bar, said bar of greatestlength being provided with a contact outwardly adjacent the bar ofshortest length, and a combined snapping, snap regulating and circuitopening and closing mechanism carried by the ba'r of shortest length forcoaction with said contact and including resilient pressure controlledShifters, said mechanism having its operation controlled by thethermostatic movements of said bars.

8. In a thermostat, a pain of thermostatic bars,

means for anchoring one end of the bars together and for maintaining thebars in parallel spaced relation, a resilient setting structure for saidbars, said structure being anchored to one of the bars, extendingthrough the other bar and bearing on the latter, a positioning pinanchored to one of said bars and extending through the other, and amultiplying arm having its body corresponding to the body of either ofsaid bars, said multi; plying arm extending between said bars andprojecting from the other ends of the bars, said arm at its inner endbearing against said pin, mounted intermediate its ends on an element ofsaid structure and having its outer end provided with an opening for thereception of a controlling eleu ment, said arm bearing at its inner vendagainst the inner face of one of said bars and bearing intermediate itsends upon the other of said bars.

9.Y In a thermostat, a pair of thermostatic bars, means for anchoringone end of the bars together and for maintaining the bars in parallelspaced relation, a resilient setting structure for said bars, saidstructure being anchored to one of the bars, extending through the otherbar and bearing on the latter, a positioning pin anchored to one of saidbars and extending through the other, and a multiplying arm having itsbody corresponding to the body of either of said bars, said multiplyingarm extending between said bars and projecting from the other ends ofthe bars, said arm at its inner end bearing against said pin, mountedintermediate its ends on an element of said structure and having itsouter end provided with an opening for the reception of a controllingelement, said arm bearing at its inner end against the inner face of oneof said bars and bearing intermediate its ends upon the other of saidbars, said arm being formed of a pair of branches disposed in angularrelation.

10. In 'a thermostat, a pair of thermostatic bars, means for anchoringone end of the bars together and for maintaining the bars in parallelspaced relation, a positioning pin anchored to one of said bars andextending through an opening in the other of said bars, said pin beingof less diameter than said opening, a resilient setting structure forsaid bars, said structure including an element anchored at one end toone of the said bars said bars and with-such openingibeing of greaterdiameter than said element, and a multiplying arm of thermostaticcharacteristics extending between and projecting from said bars foroperating a. controlling element, said arm having its inner end bearingagainst the inner face of one of said andextending'- through an openingin the other of bars and at a point adjacent its inner end bearingagainst the inner face of the other of said bars, said arm having itsinner end bearing against said pin formed with an opening for thepassage of said element and with the opening being of greaterdiameterthan the diameter of said element.

.11. In a thermostat, a pair of thermostatic bars, meansy for anchoringone end of the bars tomaintaining `them in parallel ing means forregulating the snapping movement of said structure.

l2. In a thermostat, a pair of thermostatic bars, means for anchoringone end of the bars together and formaintaining them in parallel spacedrelation, one of said bars being of greater length than and extendedbeyond the other end of the r bar, that bar of greatest length beingprovided With a contact positioned beyond the bar of shortest length, aContact movement of the latter.

GEORGE W. WHI'I'EHURST.

